Total hip arthroplasty (THA) volumes continue to rise each year as the population ages and indications broaden. Increasingly, younger patients require hip replacement for conditions beyond primary osteoarthritis or fractures. As a result, the number of revision procedures is growing and is expected to increase further.

Prospective data collection within this population will enable us to address key uncertainties, particularly around optimal implant selection for complex primary and revision cases.

In addition, establishing a structured prospective database will allow for systematic internal auditing for quality assurance. Even simple metrics - such as verifying whether every patient received a complete diagnostic infection workup before revision surgery - could immediately enhance service quality and inform improvements to clinical pathways.

Total hip arthroplasty (THA) volumes continue to rise each year as the population ages and indications broaden. Increasingly, younger patients require hip replacement for conditions beyond primary osteoarthritis or fractures, including developmental dysplasia, avascular necrosis, post-traumatic deformities, and sequelae of childhood diseases such as femoro-acetabular impingement, septic arthritis, Legg-Calvé-Perthes disease, and slipped capital femoral epiphysis.

As a result, the number of revision procedures is growing and is expected to increase further. Two distinct patient groups drive this trend. First, individuals who received a primary THA in their 60s or 70s frequently require revision in their 80s or 90s, where reduced physiological reserve and multiple comorbidities create specific perioperative challenges. Second, patients who undergo THA at a young age - often due to congenital or childhood pathology - have a long life expectancy and a higher probability of needing revision surgery later on.

University Hospitals Leuven receive a substantial share of these complex cases, given our expertise in complex primary and revision hip arthroplasty and our multidisciplinary, patient-tailored approach.

However, the heterogeneity of these patients - due to varying indications, implant types, bone defects, and previous procedures - makes randomized controlled trials in this field difficult to conduct. Consequently, many clinical questions remain unresolved.

Prospective data collection within this population will enable us to address key uncertainties, particularly around optimal implant selection for complex primary and revision cases.

In addition, establishing a structured prospective database will allow for systematic internal auditing for quality assurance. Even simple metrics - such as verifying whether every patient received a complete diagnostic infection workup before revision surgery - could immediately enhance service quality and inform improvements to clinical pathways.

Inclusion Criteria:

• Patients undergoing a hip replacement for the following indications:

  1. THA with hardware removal

  2. THA for hip dysplasia

  3. THA with femoral deformity or prior corrective surgery

  4. THA after LCPD, SCFE or septic arthritis

  5. THA in metabolic disease

  6. THA in hyperlaxity (e.g. Ehlers-Danlos syndrome, Down syndrome)

  7. THA with complex bony anatomy

  8. THA in patients aged 25 years or younger

  9. Other indications for which the treating surgeon expects increased surgical difficulty or increased risk of postoperative complications

     Exclusion Criteria:

• Patients unable to provide written informed consent

• Patients who prefer treatment outside of University Hospitals Leuven

• Patients with proven PJI according to the 2021 EBJIS criteria

• Patients undergoing standard, non-complex, hip replacement as judged by the treating physician.

Every patient, regardless of sex or age, undergoing complex primary THA or aseptic revision hip arthroplasty, is eligible for inclusion in this study. This study will therefore also include children and women of childbearing age, although this is expected to be extremely rare. The decision on whether a primary hip replacement is categorized as a complex procedure is left to the discretion of the treating physician.